<div>On Thu, Dec 18, 2008 at 4:15 PM, Henning Thielemann<br>
&lt;<a href="mailto:schlepptop@henning-thielemann.de" target="_blank">schlepptop@henning-thielemann.de</a>&gt; wrote:<br>
<br>
</div><div>&gt; In C/C++ referential transparent functions code can be declared by<br>
&gt; appending a &#39;const&#39; to the prototype, right?<br>
<br>
</div>For one thing, some fields in a const C++ object can be explicitly set<br>
mutable. mutable is sometimes used in C++ a similar way to<br>
unsafePerformIO in Haskell. You have something that uses mutability in<br>
its internals but that mutability shouldn&#39;t be observable to the<br>
caller. In both cases you have no means of actually ensuring that the<br>
mutability is actually unobservable.<br>
--<br>
<font color="#888888">Dan<br>
</font></blockquote></div></div></div><br></div>
</div><br>